Yeah, and now if something doesn't have enough to do 4k there's:

a) nothing stopping them from faking it, plenty of crappy hardware will record files in an upscaled resolution (see webcams especially for this)

b) you probably don't want a larger version of the output of that device anyways.

I mean even a 130 dollar phone has a 13 megapixel camera. https://www.amazon.com/BLU-Android-Factory-Unlocked-Display/...